101 Things You Didn't Know About Da Vinci (16 page)

The ability to reprint ancient treatises and documents also factored in to the aims of the Renaissance—the classics could be brought to life. People could read Vitruvius, Aristotle, and other ancient Greeks and Romans. In addition, wealthier people who already had access to books started requesting a greater variety of literature, in different languages. There was suddenly a demand for poetry! Almanacs! Many new types of books were created, and they quickly became popular.

Always true to form, Leonardo approached the printing press critically. The predecessor to the printing press was block printing, a method where a block of wood would be carved out to leave raised letters. In Gutenberg's updated printing press model, letters (type) were placed by hand along a track, and these letters were movable, meaning they could be reset for each new page of text. While Leonardo didn't propose completely reinventing the printing press, he had an idea to add a second track that would increase the machine's efficiency He wanted to publish a treatise on this idea, but like most of his works, it remained undiscovered until well after his death.

The printing press had immense ramifications for Leonardo's future work. And everyone—future artists, inventors, school children—has benefited from being able to read the master's original work.

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Under the boardwalk, down by the sea

Leonardo was a considerate soul. Not only was he interested in the design of boats and other watercraft, he also thought about the needs of sailors themselves. One thing we can't credit Leonardo with, though, is inventing diving. The ancient Greeks used a technique called breath-hold diving to search for food, gather sponges, and perform military reconnaissance. The Greeks and Romans swam underwater to escape enemy detection, probably by breathing through reeds. Some people supposedly experimented with breathing from an air-filled bag underwater, but the recycled carbon dioxide likely put an end to those trials.

Swimming, diving, and generally working with water were ideas Leonardo pursued constantly. He tried to expand the length of time someone could stay underwater, and he also wanted to find ways to protect the submerged diver. Aside from dangerous fish, there were underwater plants to brush against, sharp rocks to step on, and too many other obstacles. Many of Leonardo's oceanic inventions were never tested, but some are quite similar to actual devices that can be purchased today.

One of his most futuristic ideas was a full deep-sea diving suit. Preliminary research into deep-sea exploration was beginning to take hold in the Renaissance, and Leonardo's ideas were influenced by this new interest in visiting the ocean depths. As with most things of a technological nature, the primary impetus (and, in most cases, funding) was likely the military. Italians had to become smarter about their battles, and water approaches were one way to take advantage of the natural terrain.

Leonardo's sketches show divers who were basically frogmen, prepared for land and sea at the same time. Their diving suits included land requirements such as regular clothes, ropes, and weapons. He also sketched out an “air sack” that may have sparked later inventors to create oxygen tanks. One such diagram shows the diver with a large, impact-resistant air tank attached to his chest so that he could dive far beneath the surface, but this chamber was so bulky, swimming with it might have been impossible! Leonardo's suit was to be made of leather or other durable animal skin, and cane hoses allowed the diver to move and breathe easily. He tried to reinforce these connections with metal, so that the pressure of being deep underwater wouldn't threaten the diver's safety. It seems Leonardo intended this suit for relatively shallow diving, because the pipe providing air to the diver went directly to the surface. The top of the tube also featured a bell-shaped float, so that the air openings would always remain above water. Modern divers have actually built a suit from Leonardo's notes, and they reported that it functioned quite well.

In true biblical spirit, Leonardo developed ideas in 1480 to let humans walk on water. Unlike Jesus, though, Leonardo's water walkers had to use special floating devices to keep them from sinking. This addition probably kept Leonardo from being deemed a heretic, and also added a touch of practicality, if you can call it that. These floats would have been attached to the feet of the user, who would have balanced by holding on to long poles. Not surprisingly, Leonardo doesn't seem to have ever built or tested a real version of this device.

Many of Leonardo's sketches for water-based machines focused on convenience. For example, he designed a glove with webbing in between the fingers, imitating a duck's webbed feet. These gloves would have been worn in the water, creating smoother and faster self-powered transportation. They also would have spared the wearer's hands from sticks, stinging fish, and other hazards. One of his sketches shows gloves proportionally as large as the flippers that swimmers wear on their feet! He also designed a life preserver that would allow people to remain afloat while in the water. While some of his inventions seem outlandish, others were practical and useful—the dreamer definitely had his pragmatic side.

63
Containing the forces of nature

Water: the basis for all life on earth, the universal solvent, and a general requirement for all living things. It has fascinated humans throughout recorded history, and Leonardo was no exception. He went to great depths to study water and all its properties. His observations were right on target. For example, he noted that water could easily change in character depending on the environment. Leonardo studied the various ways in which water came from the heavens, noting it could fall as rain, melt as snow, run in rivers, and actually come from the earth itself. He understood water's power to revitalize plants and people, but he was also aware of its ferociousness, as we can tell from his studies of storms and his sketches of powerful swirling waves.

Like his interest in blood flow and circulation, Leonardo was interested in river flow and water motion. As an artist he was always in motion, so you can definitely see the correlation. He studied currents and waves, observing how surfaces that repeatedly came into contact tended to degrade over time. He may have actually been the first to suggest the concept of erosion, and realizing how destructive water can be, he probably even feared the disaster caused by swollen rivers. As it turns out, his concern was well founded. The Arno River, near Florence and Pisa, erupted over its banks at least twice during Leonardo's lifetime, once in 1466 and again in 1478. These cataclysmic events influenced Leonardo's water management and manipulation designs.

One of his grandest ideas to control water was a scheme to divert the actual path of the Arno River. Leonardo was in Imola in 1502, working as the chief engineer for Cesare Borgia. During this time he used his skills in cartography to accurately plot out the course of the river, and in 1503 he presented a plan to redirect the river between Imola, Florence, and the sea. He had the support of influential Renaissance politician and philosopher Niccolo Machiavelli. Leonardo and Machiavelli were two of the most respected figures of the day, and their positions lent significant authority to their scheme.

At one point, Leonardo also decided to revamp the Florentine canal system. The general goal was to construct a series of channels that, passing through Pisa, would eventually lead to the sea. This effort would have improved the city's waterpower and irrigation, in addition to the commercial benefits. These canals would have used steps and locks powered by oversized siphons. In his engineering studies, Leonardo suggested digging large ditches that would eventually connect to the river. Ships could have sailed through Florence and into the hillier, mountainous areas for easier pickup and delivery of goods. It also would have helped with the Florentine wartime effort.

Unlike many of Leonardo's projects, this one was at least started! Hundreds of men began working on the canals under the supervision of Colombino, a master hydraulic engineer. Unfortunately, these canals were never completed, as Leonardo had to return to Florence to work on a fresco in the Palazzo Vecchio. In Leonardo's absence, Colombino took a few liberties with the design and made some disastrous engineering changes. According to some reports, the Arno actually did flow into its new path for a short time, but the river promptly reverted to its previous course and the project was eventually abandoned.

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Harnessing the power of water

On dry land, Leonardo spent time studying and designing aircraft, including elaborate helicopters, gliders, and parachutes. Never one to limit himself, he was also fascinated with aquatics and devoted years to designing machines that worked with water. Given the sheer amount of water surrounding Italy, he picked a great hobby. It is likely that he was first exposed to aquatic engineering while apprenticed to Verrocchio, who was, among other things, a hydraulics engineer.

Why this interest in aquatics? From his observations, Leonardo knew water was inherently contradictory. He described it as the
vetturale di nature
(vessel of nature). It's only fitting that such a force of nature would have intrigued Leonardo. Between about 1485 and 1490, Leonardo developed several schemes for machines that worked in water. One design was for a water pump that could drain an entire port! This pump would have been useful when pylons had to be driven into water, or when a building's foundation had to be built underwater. He also developed pumps that could remove water from a ship (or anyplace else) through a valve.

Leonardo's “Codex Atlanticus” contains many designs for water-controlling devices. For example, he came up with several ideas for sluice gates, or movable panels, that could drop down to divert the flow of a river or canal. He also made detailed three-dimensional sketches for dredges (machines that could clean the bottom of locks and canals), which used mooring ropes to wind up the dredge and force it along the shoreline to the next point.

Some of Leonardo's drawings show machines that use water to achieve another purpose. He sketched a hydraulic saw that used water to power the blade; this device could have been used for cutting logs and other large objects. He also worked on a design that improved the Archimedian screw, an ancient device used to pump water out of a well or uphill. This design was similar to both his helicopter studies and a later waterwheel design. Waterwheels, though developed years before the Renaissance, were of great interest because of their capacity to quickly replenish supplies (such as the local water tower) that could be exhausted during battle.

Leonardo also created a water clock, which set off an alarm based on the amount of water flowing from one container to another. At its most basic, the water clock consisted of a stone jar or other container from which water dripped. A second vessel was filled at a continuous rate. As the volume of water increased, people could use markings inside the container to see how much time had passed. It might not have the cachet of an hourglass, but it apparently worked quite well if you didn't mind the sound of dripping water!

65
The ocean liners of the future

Being the all-around inventor that he was, Leonardo tried his hand at designing all sorts of vehicles. He sketched schematics for many types of land- and watercraft, including the world's first paddleboat. His three-dimensional pen-and-ink sketches dating to 1482 show a pointed hull—a smart design idea, since it increased speed and enhanced navigation. He thought that if a boat could be propelled with paddles mounted on a rotating cylinder, the boat could move faster and more smoothly than with oars. His sketches were highly detailed in some places; he specified gears, belts, and large cylinders connecting the entire assembly.

Hull designs for ships were not new—even Stone Age humans figured out how to carve out the inside of a tree and use it for a canoe. Leonardo added his own special flare by improving on existing hull designs in both shape and ergonomics. In addition to a single-hull design, Leonardo sketched out a double hull that would make the ship stronger and better able to ward off enemies. This idea has endured into modern times, double-hull steel ships being quite common. He also worked on ways to resurrect sunken ships, one of which involved attaching tanks filled with air to the sides of a ship. The idea was that after an attack, ships could simply use these tanks to float back to the surface.

Some of Leonardo's designs for watercraft weren't even meant for people. He knew that Italy was industrializing, and a major side effect was that goods had to be transported. He made some sketches showing a float for transporting building materials down a river. A dropped bottom provided space for either passengers or military personnel. Another revolutionary design was for a partial submarine, or semisubmersible. Though it was intended for battle, only a couple of people could fit inside it. Like modern submarines, it did have a tower leading to the surface, but the similarity ended there.

Leonardo was definitely a proponent of “think big!” One of his largest boat designs was for a war ship that served as a battering ram. Leonardo's drawings show an oversized rotating scythe, operated by a gear-based mechanism that raised and lowered it. Leonardo's attention to detail is evident in this design, which also includes shields for the oarsmen. Modern-day descendents from these battleships were built in the mid-nineteenth century, including the ironclad giants such as the USS
Monitor
. This type of warship is largely obsolete now due to the emergence of more flexibly designed aircraft carriers.

66
Around and around we go

The wheel is perhaps the undisputed champion of inventions. It has influenced virtually every part of civilization, from politics and government, to housing and recreation. Wheels are used in almost all forms of transportation: cars, trains, airplanes, and anything else that needs to move along a firm surface. Imagine a modern commute without bicycles, cars, and buses. Wheels are central to manufacturing and mass production, and most of us couldn't earn a living without them.